Feb. 28, 1916 
An Asiatic Species of Gymnosporangium 
1005 
Haraeanum. Clinton (2) later admitted that he confused two species, 
but believed Long not justified in describing the leaf form as new and 
considered G. chinense Long as synonymous with G. Haraeanum. 
The branch form, G. japonicum , has recently (May 19, 1915) been 
collected on the campus of the University of Washington, at Seattle, 
Wash., by Dr. J. W. Hotson, and a specimen of it is in the herbarium 
of Dr. J. C. Arthur and has been examined by the writer. 
OCCURRENCE IN OREGON 
In the spring of 1915 (Mar. 29) the writer again visited the locality 
from which he had previously collected the material of Roestelia koreaensis. 
Within 20 feet of the two Japanese pear trees which had shown the 
infection the previous season and about midway between them two 
trees of Juniperus chinensis were found which showed abundant infection 
on the leaves of a telial stage of a species of Gymnosporangium. This 
was determined as G. Haraeanum. At the time the collection was made 
most of the sori had become swollen into gelatinous masses of character¬ 
istic shape (PL LXXVIII, fig. 3), though a few were found which had 
not become expanded (PI. LXXVIII, fig. 2). No other species of 
Gymnosporangium was found in the vicinity, and no evidence of a 
branch form was noted. 
A considerable quantity of this material was taken to the laboratory 
of the Department of Botany and Plant Pathology at the Oregon Agri¬ 
cultural College and used in greenhouse infection experiments. No 
plants of Pourthiaea villosa were available, but four potted plants of 
Pyrus sinensis and one each of Pyrus communis and Cydonia vulgaris 
were used in the experiments. 
The method used was that of suspending branches of the infected 
juniper over the trees and covering them with large bell jars. This was 
done on March 30. These were left over the trees for four days, during 
which time the jars were removed for a few moments daily and the foli¬ 
age and the inside of the jars sprayed with water. The plants were left 
covered longer than was intended, it having been the original plan to 
leave them covered only two days. At the time they were removed it 
was noted that evidence of infection was already visible on the foliage 
of the Japanese pear trees. Three or four days later it was evident that 
pycnia were developing in great abundance on the foliage of these and a 
few on the quince. There was evidence of initial infection on the trees 
of Pyrus communis , but no pycnia ever developed; only minute black 
spots finally resulted. 
Fully developed ascia were collected from the infected trees of Pyrus 
sinensis (Pl. LXXIX, fig. 1) and Cydonia vulgaris (PL LXXIX, fig. 2) 
on June 3, though they were mature fully three weeks earlier. The 
resulting aecia were found to agree in all respects with the aecia collected 
in the field the previous year and with descriptions of Roestelia koreaensis. 
